The invention is directed to a room air conditioner and more particularly to a room air conditioner having foamed insulation walls forming at least a portion of the air passage within the air conditioner.
Room air conditioners generally have an air inlet and an air outlet at a front side of the air conditioner which faces the interior of the room when the air conditioner is positioned in a window opening or in a through the wall sleeve. Usually warm air is drawn in through a portion of the front panel to pass through a filter and through the evaporator coil to be cooled and then is directed by a blower or fan to an outlet or outlets, also in the front panel. The outlet may be a single opening positioned either along a top or bottom edge of the front panel or may be a single opening positioned at one side or the other of the front panel. Occasionally the air from the blower is directed into a manifold type box or plenum chamber and from that chamber it is allowed to exit through the front of the air conditioner through more than one opening. For example in U.S. Pat. No. 3,472,149, assigned to the assignee of the present invention, air is drawn into the air conditioner unit through a lower front grill portion and is redelivered to the room through a grill portion which extends along the top edge of the air conditioner.
In U.S. Pat. No. 2,737,788, air is drawn in from a front lower grill opening, through a filter and the air is pressurized by a fan mounted in a manifold chamber or plenum from which air is permitted to exit through two spaced grills. In U.S. Pat. No. 4,492,094 air is drawn in through a front grill, is pressurized by a fan and exits through a grill 30 located at a bottom edge of the front panel. FIGS. 1 and 2 of that patent illustrate prior art constructions of top and side return of cooled air to the room.
The use of a plenum chamber or similar structure requires an extra space in the air conditioner thereby reducing the compactness of the air conditioner and adding to bulkiness. Also such a structure requires extra parts and weight, thus increasing the costs and complexity of manufacturing. Oftentimes, particularly when the air outlet is positioned on a single side of the air conditioner, the air is drawn into the air conditioner evaporator coil in an off-center fashion thereby reducing the efficiency of the air conditioner.
The use of a foamed insulation material such as expanded polystyrene for forming various portions of the air passage within the air conditioner is known. For example, U.S. Pat. No. 2,989,855 utilizes an air deflector member positioned in the air outlet plenum chamber which forms three walls of the chamber and which includes a plurality of air directing vanes. U.S. Pat. No. 4,100,764 discloses the use of a multiple number of insulation boards formed of polystyrene resin foam including an interior fan case which houses the fan used to recirculate interior air and which housing surrounds a portion of the blower wheel. The housing forms a single volute opening and directs air up through a partially insulated passage to pass through the evaporator before returning to the room. The insulation boards are to be provided with a plurality of projections and grooves corresponding with each other and with portions of the refrigeration components so that the components are fixedly interposed therebetween, when assembled.
U.S. Pat. No. 3,938,348 discloses the use of a number of walls formed of insulating material including a wall positioned below the evaporator upon which condensed water will collect and which then passes through a water trap being a tube with U-shape bend in it to permit passage of condensed water from the evaporator portion of the air conditioner, through a barrier wall and into the compressor/condenser portion of the air conditioner.